Aquatic Turtle Community Dynamics in Relation to Reintroduction of Alligator Snapping Turtles, Macrochelys Temminckii
Aquatic Turtle Community Dynamics in Relation to Reintroduction of Alligator Snapping Turtles, Macrochelys Temminckii

Author: Travis L. Anthony

Publisher:

Published: 2013

Total Pages: 114

ISBN-13:

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The alligator snapping turtle (Macrochelys temminckii) is a long-lived species that merits reintroduction because the species has declined significantly throughout its range. The purposes of this study were to: 1) report the findings of a reintroduction project that was initiated in 2008 and 2) to compare habitat associations of all aquatic turtles species in the Caney, Verdigris, and Spring rivers in northern Oklahoma. Alligator snapping turtles were released in the Caney River in 2008, 2009, 2010, and all released individuals exhibited substantial annual growth rates upon recapture 1-3 years later. Additionally, no decline in body condition was observed. Capture probability was estimated to be 30%, and annual survival was estimated to be 64%. This survival estimate may be lowered by dispersal of animals away from the sampling area. Among the three rivers and three tributaries sampled, Pond Creek, a tributary of the Caney River, had the highest diversity. Big Creek, a tributary of the Verdigris River, supported a turtle community that was comparatively dissimilar to other sites sampled, including in comparison to the main channel of the Verdigris River. Possible displacement of Ouachita map turtles (Graptemys ouachitensis) was observed where alligator snapping turtles were introduced.

Diet and Feeding Behavior of Juvenile Alligator Snapping Turtles (Macrochelys Temminckii) in Eastern Oklahoma
Diet and Feeding Behavior of Juvenile Alligator Snapping Turtles (Macrochelys Temminckii) in Eastern Oklahoma

Author: Mitchell B. East

Publisher:

Published: 2012

Total Pages: 158

ISBN-13:

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In Oklahoma, the alligator snapping turtle (Macrochelys temminckii) has experienced declines and recent efforts to conserve the species have focused on reintroducing captive-reared juveniles. The effect of the reintroduction on other aquatic turtles is not known and feeding behavior of juvenile M. temminckii is not understood. The following studies were conducted to 1) compare the diet of captive-reared juvenile M. temminckii to that of wild juveniles and investigate the diet overlap of juvenile M. temminckii with adult female Graptemys ouachitensis in the Caney River, where M. temminckii have been recently reintroduced, in comparison to Sequoyah National Wildlife Refuge (SNWR) where the two species have co-occurred indefinitely, ; 2) determine if juveniles reared with exposure to a single food item exhibit innate feeding preferences; and 3) define the current status of aquatic turtles at SNWR in comparison to data collected a decade ago. There were noticeable differences between the diet of captive-reared and wild juvenile M. temminckii. There was greater overlap of juvenile M. temminckii and adult female G. ouachitensis diet at the Caney River. Juvenile M. temminckii showed some innate prey preference and foraging capability. There were large declines in trapping rates of all species, composition of the aquatic turtle community changed dramatically, and changes in the M. temminckii population indicate that unknown factors have impacted turtles at SNWR.

Nesting Ecology in Reintroduced Alligator Snapping Turtles (Macrochelys Temminckii)
Nesting Ecology in Reintroduced Alligator Snapping Turtles (Macrochelys Temminckii)

Author: Jessica Leigh Miller

Publisher:

Published: 2012

Total Pages: 120

ISBN-13:

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The alligator snapping turtle (Macrochelys temminckii) is a large freshwater species that has experienced population declines throughout much of its range. In an effort to reestablish an extirpated population in southern Oklahoma, adult M. temminckii were released at Tishomingo National Wildlife Refuge in 2007. I investigated several aspects of M. temminckii reproductive biology within this reintroduced population, including nest-site selection, reproductive and nest predation rates, and patterns of temperature-dependent sex determination (TSD) in natural nests. Water depth two meters from the shoreline and percentage ground cover were important factors in nest-site selection. The nest predation rate was 76% when efforts were made to protect nests and the average clutch size in intact nests was 22.4 eggs. The overall sex ratio in 2010 recruits was strongly female-biased (91.8% female) and a strongly skewed population sex ratio may become a serious threat to this reintroduced population if this trend continues. I also developed a technique to reliably estimate clutch size from predated M. temminckii shell fragments which will improve estimates of mean clutch size (and therefore annual fecundity) for the population. The persistence of several adult M. temminckii and evidence of successful reproduction and recruitment are positive signs, but post-release monitoring will need to continue for several more years in order for this reintroduction to be considered a success.

Relative Abundance, Population Structure, and Habitat Utilization of the Alligator Snapping Turtle (Macrochelys Temminckii) and Eastern Snapping Turtle (Chelydra Serpentina) in Southeastern Missouri
Relative Abundance, Population Structure, and Habitat Utilization of the Alligator Snapping Turtle (Macrochelys Temminckii) and Eastern Snapping Turtle (Chelydra Serpentina) in Southeastern Missouri

Author: Timothy Charles Lescher

Publisher:

Published: 2010

Total Pages: 75

ISBN-13:

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Alligator Snapping Turtles have not been surveyed extensively in Missouri since 1993-94. Six sites that were sampled in the early nineties were re-sampled in 2009 at the same locations where previous researchers trapped. Significantly fewer significantly fewer Alligator Snapping Turtles were captured per trapnight at all six sites. The population structure of the Alligator Snapping Turtles had a significantly different distribution in 2009 compared to 1993-94. The population structure had shifted toward smaller individuals, and fewer adult males and adult females were captured in 2009 compared to 1993-94. The 1993-94 structure was normally distributed while the 2009 structure exhibited a negative skew. Populations sampled in 2009 have an extremely female-biased sex ratio and fewer large adults, which may impact the population negatively in the future. Future sampling of Alligator Snapping Turtles at these six sites is recommended to continue monitoring their long-term trends in relative abundance and population structure. Alligator Snapping Turtles (Macrochelys temminckii) and Eastern Snapping Turtles (Chelydra serpentina) were captured during the summers of 2009 and 2010. Habitat characteristics were collected at each trap that captured these species. Subsequent analysis of data revealed that Alligator Snapping Turtle presence at trap sites was characterized by increased physical structure in the stream, water depth, relatively high levels of detritus, and warmer temperatures when compared to Eastern Snapping Turtles; the amount of aquatic vegetation and bottom surface (i.e., mud or non-mud substrate) were important in characterizing Eastern Snapping Turtle presence in traps. Eastern Snapping Turtles and Alligator Snapping Turtles did not use the same areas spatially, and were only trapped at the same location once in 557 trapnights. Future conservation plans for the Alligator Snapping Turtle and Eastern Snapping Turtle should consider the microhabitat characteristics of sites utilized by these turtles, along with the possibility of interspecific interactions within Chelydridae.

The Ecology, Exploitation and Conservation of River Turtles
The Ecology, Exploitation and Conservation of River Turtles

Author: Don Moll

Publisher: Oxford University Press

Published: 2004-04-08

Total Pages: 408

ISBN-13: 0195102290

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The underlying theme of this book is that a widespread, taxonomically diverse group of animals, important both from ecological and human resource perspectives, remains poorly understood and in delcine, while receiving scant attention from the ecological and conservation community. This volume proposes a comprehensive overview of the world's river turtles' ecology, conservation, and management. It begins with a categorization of taxa which inhabit flowing water habitats followed by information on their evolutionary and physical diversity and biogeography. Within the framework of ecology, the authors discuss the composition of river turtle communities in different types of lotic habitats and regions, population dynamics, movements, reproductive characteristics and behavior, predators, and feeding relationships. In a conservation and management section, the authors identify and evaluate the nature and intensity of factors which threaten river turtle survival--almost all of which involve direct human exploitation or indirect effects of human induced habitat alteration and degradation. They then list and evaluate the various schemes which have been proposed or employed to halt declines and restore populations, and make recommendations for future management plans for specific species and regions. In closing, they state their viewpoint concerning future research directions and priorities, and an evaluation of future prospects for survival of the world's river turtle species.

Reproductive Biology and Conservation Genetics of the Alligator Snapping Turtle (macrochelys Temminckii)
Reproductive Biology and Conservation Genetics of the Alligator Snapping Turtle (macrochelys Temminckii)

Author: Amber R. Teare

Publisher:

Published: 2010

Total Pages: 91

ISBN-13:

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Author's abstract: The alligator snapping turtle (Macrochelys temminckii) is a highly aquatic turtle only found in Gulf of Mexico drainages. The biology of this species remains relatively unknown, despite years of harvest and use as a zoological attraction. The purposes of this study were to (1) determine gender size classes and assess sexual size dimorphism, (2) delineate the reproductive cycle of M. temminckii, particularly their sex steroid seasonality, and (3) evaluate possible genetic divergence between M. temminckii found in southwest Georgia and northern Florida. Alligator snapping turtles exhibit pronounced sexual size dimorphism as adults. However, determining sex in smaller individuals is difficult. The purpose of this study was to assess gender size classes and sexual dimorphism in Macrochelys temminckii. Alligator snapping turtles in southwest Georgia were trapped from March 2008 to April 2010. Captured turtles were bled, sexed based on size and ultrasound, and measured for multiple characteristics. For all measurements, adult males were larger than females. The relationships between carapace length, plastron-to-vent length, and testosterone levels were used to determine gender of smaller individuals. To ensure accurate sexual assignment when studying M. temminckii, data from multiple methods (morphological measurements, ultrasonography, testosterone levels, and, laparoscopy) should be used. To delineate the reproductive cycle of M. temminckii, blood samples were taken from captured individuals, and plasma testosterone and estradiol were measured using enzyme immunoassay. Males exhibited seasonal changes in testosterone levels, with maximum levels occurring in October. Mating behavior was elucidated from the appearance of wounds on males that only occurred in April. Females displayed seasonality in testosterone and estradiol levels, with relative peaks occurring in March and April (mating and ovulation) and September and October (follicular development). Genetic structure between M. temminckii populations separated by a dam and under different hunting pressures was assessed using microsatellite loci. Average number of alleles per locus and number of unique alleles was higher for the Florida population. Genetic structure was detected between the populations (FST = 0.043, p = 0.001). The rapid development of structuring between Florida and Georgia M. temminckii warrants further investigation into the effects of fragmentation and overexploitation on this species.

Species Profile: Alligator Snapping Turtle (Macroclemys Temminckii) on Military Installations in the Southeastern United States
Species Profile: Alligator Snapping Turtle (Macroclemys Temminckii) on Military Installations in the Southeastern United States

Author:

Publisher:

Published: 1997

Total Pages: 20

ISBN-13:

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The alligator snapping turtle (Macroclemys temminckii) is an uncommon turtle of the Southeast that is a former candidate species for listing as threatened or endangered by the U.S. Fish and Wildlife Service. The species is found in the south-central and southeastern United States throughout the Mississippi River Valley and Gulf Coast States. Alligator snapping turtles utilize a variety of aquatic habitats having permanent water and abundant aquatic vegetation, including rivers, streams, canals, lakes, oxbows, and sloughs. Nests usually are located near water on high and well-drained sites such as natural or artificial berms bordering aquatic environments. The alligator snapping turtle has been documented on several military installations in the Southeast. This report is one of a series of 'Species Profiles' being developed for threatened, endangered, and sensitive species inhabiting southeastern United States plant communities. The work is being conducted as part of the Department of Defense (DoD) Strategic Environmental Research and Development Program (SERDP). The report is designed to supplement information provided in plant community management reports for major United States plant communities found on military installations. Information provided on the alligator snapping turtle includes status, life history and ecology, habitat requirements, impacts and cause of decline, management and protection, and inventory and monitoring.

Ecology of Hatchling Alligator Snapping Turtles (Macrochelys Temminckii)
Ecology of Hatchling Alligator Snapping Turtles (Macrochelys Temminckii)

Author: Sarah Spangler

Publisher:

Published: 2017

Total Pages: 132

ISBN-13:

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Little is known about the first year of life for many of the world’s freshwater turtles. This is due in part to their cryptic nature and the difficulty of locating hatchlings in the wild. The lack of information about this demographically important age group has led researchers to draw conclusions from indirect inferences about survival rates and ecological roles of hatchlings that may or may not be accurate. To begin filling in some of these gaps, I focused on the first year in an alligator snapping turtle’s life. I studied: (1) circadian and circannual patterns of activity, (2) growth rates and how they are related to activity rates, (3) habitat preferences, (4) fall movement patterns, and (5) predation patterns. My study site was within the species’ natural range in southeastern Oklahoma. Unlike adults, hatchlings followed a predominantly diurnal activity pattern for much of the year, with peak activity occurring during the mid-hours of the day. The diurnal habit of hatchlings may be a strategy to temporally partition themselves from nocturnal predators. There were no significant relationships between growth rates and activity rates during any period, potentially due to small sample size. Hatchlings were located in areas of increased cover and shallower water depths, when compared to random locations. Their movement patterns were characterized by an initial movement away from the site of release to a location with suitable habitat characteristics, and they tended to stay at these locations for extended periods. I documented depredation by fish, but not by terrestrial predators such as raccoons.

Stress and Body Composition of Juvenile Alligator Snapping Turtles (Macrochelys Temminckii)
Stress and Body Composition of Juvenile Alligator Snapping Turtles (Macrochelys Temminckii)

Author: Brandon Tappmeyer

Publisher:

Published: 2019

Total Pages: 102

ISBN-13:

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The alligator snapping turtle (Macrochelys temminckii), is a species of conservation concern that is the subject of multiple head-start and reintroduction efforts across its range. In captive propagation programs, producing offspring that are in optimal physiological condition maximizes the likelihood of success after release. The purpose of my study was to compare stress and body composition between one free-ranging reintroduced population and two captive populations. The two captive populations were both housed in southern Oklahoma, but one group was reared indoors whereas the other inhabited outdoor ponds at a national fish hatchery. I used circulating glucocorticoid (corticosterone) concentrations as an indicator of stress level and dual-energy X-ray absorptiometry (DXA) to estimate body composition. Corticosterone concentrations did not differ between captive and free-ranging populations, possibly suggesting that corticosterone is a poor predictor of stress in this species or under chronically stressful conditions. DXA accurately and precisely estimated fat mass (FM), lean tissue mass (LTM), and bone mineral mass (BMM). The captive-outdoor and free-ranging populations exhibited greater BMM than the captive-indoor population. However, both captive populations exhibited higher FM and lower LTM than turtles in the free-ranging population. A body condition index calculated by regressing log-transformed mass on length did not correlate with FM or BMM, but did correlate significantly with LTM.

Habitat Use and Movements of Alligator Snapping Turtle (Macrochelys Temminckii) Hatchlings
Habitat Use and Movements of Alligator Snapping Turtle (Macrochelys Temminckii) Hatchlings

Author: Amity Ann Bass

Publisher:

Published: 2007

Total Pages: 106

ISBN-13:

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The objective of this study was to gather data concerning home range, movements, and habitat use of hatchling Alligator Snapping Turtles ... in order to better manage for this species. Nineteen hatchlings were tracked at Black Bayou Lake National Wildlife Refuge during 2006. Ten animals were successfully tracked during the spring and nine during the fall. Hatchlings that were incubated in the laboratory or naturally on the railroad causeway were heavier and had longer carapace lengths than those naturally incubated along the forest-old field edge of the peninsula (p